U.S. Army Pvt. Danny Chen,19, was killed Oct. 3, 2011, in Kandahar, Afghanistan. The first of eight court-martial trials was set to begin Tuesday for U.S. soldiers accused of hazing Chen, a Chinese-American recruit, over his ethnicity until he killed himself in Afghanistan. (ASSOCIATED PRESS / U.S. Army, File)

FAYETTEVILLE, N.C. (AP) — Defense attorneys argued as an army officer’s court martial opened Tuesday that a private found dead in Afghanistan killed himself amid the stress of strained family ties and not because of alleged ethnic hazing by their client.

Sgt. Adam Holcomb of Youngstown, Ohio, is the first of eight men facing prosecution in connection with last October’s death of 19-year-old Pvt. Danny Chen. Holcomb faces several charges, the most serious of which is negligent homicide. If convicted on all charges, he faces nearly 18 years in prison.

Military officials have said the private shot himself last year in Afghanistan after weeks of emotional and physical abuse that constituted hazing.

But defense attorneys argued in opening statements that Chen told fellow soldiers he had been disowned for joining the military, which they attributed to the cause of his stress. Holcomb’s attorneys said when trial opened that the sergeant didn’t cause Chen’s death.

“There’s one and only one person responsible for the death of private Chen,” said defense attorney, Capt. Dennis Hernon. “That person is Danny Chen.”

Chen’s relationship with his family was a focal point Tuesday as 10 jurors looked on amid questioning of the man’s mother, the opening witness.

Su Zhen Chen testified Tuesday that she had had a good relationship with her son and kept in touch with him during his deployment. She said claims of strained family relations were untrue.

“He’s my only son,” Chen said in between sobs. “Why would I disown my only son?”

Prosecutors argued that Holcomb had a history of using hate speech and allegedly dragged Chen across rocky ground at one point in Afghanistan.

For months, beginning in training, soldiers in his platoon peppered him with racial insults such as “Jackie Chen” and “Dragon Lady,” his family has told authorities. On the day he died, they say he was forced to crawl about 100 yards across gravel carrying his equipment while his fellow soldiers threw rocks at him.

Chen had been deployed for two months when he was found dead in a guardhouse. Attorneys said Tuesday he shot himself in the head.

Hernon argued for the defense that Chen was an incompetent soldier, and that Chen’s superior officers took appropriate corrective actions. He also said Holcomb called Chen “Dragon Lady,” but argued that the nickname was meant “affectionately.”

Besides Holcomb, four other soldiers are also charged with negligent homicide. The judge’s decision in Holcomb’s case could be an indicator for the other soldiers.

Chen was a member of the 3rd Battalion, 21st Infantry Regiment, 1st Stryker Brigade Combat Team, 25th Infantry Division based in Fort Wainwright, Alaska, but was under the command of a Fort Bragg general in Afghanistan.

Maj. Gen. James Huggins requested the trial be transferred to Fort Bragg, which military officials said worked out better logistically.

The trial has attracted international attention, including coverage by a group of reporters from China who watched Tuesday’s proceeding.

Elizabeth OuYang, president of the New York chapter of the Organization of Chinese Americans, a nonprofit advocacy group that worked with the Chen family, accompanied the family to the court martial. She said some people in China see the trial as an indicator for how the U.S. military treats Chinese.